Diagnostic Method

Detect the trouble by calculating the time from the completion of the fuel cut to the beginning of the rear oxygen sensor voltage starting to rise.

Fig 1: Completion Of The Fuel Cut To The Beginning Of The Rear Oxygen Sensor Voltage Starting To Rise Graph

Courtesy of SUBARU OF AMERICA, INC.

• Abnormality Judgment 

  Judge as NG when the following conditions are established.

  JUDGMENT VALUE CHART
  
  

  Malfunction Criteria	Threshold Value
  The number of times that the rear oxygen sensor voltage changed to 0.3 V after the fuel cut has completed (time counter)	> 3750 time(s)

  Time Needed for Diagnosis:  10 seconds

  Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.

• Normality Judgment 

  Judge as OK and clear the NG if the following conditions are established.

  JUDGMENT VALUE CHART
  
  

  Malfunction Criteria	Threshold Value
  The number of times that the rear oxygen sensor voltage changed to 0.3 V after the fuel cut has completed (time counter)	≤ 3750 time(s)

  Time Needed for Diagnosis:  10 seconds